Detachable counterbalance-weight for motor crank-shafts



` n. s. mn. DETCHABLE COUNTERBALANCE- WEIGHT EUR MOTOR CRAN'K SHAFTS.

I APFLICATION'FILED SEPT-24, 1919. 1,350,270

Patented mag. 171511920.'

2 SHEETS-SHEET 2.

4UNITED STATES" PATENT* OFFICE.

:RoDLAND s. TRo'r'r, or DENVER, COLORADO.

DETACHAB'LE `COU'KII'YIEIRBALANCZE-WEIGHT. FOR MOTOR CRANK-SHAFTS.

To all whom t may concern',

Be it. known that I, RoLLAND S. TRo'r'r,

a citizen of the United States, residing at Denver, in the 'county of Denverand State of Colorado, `have invented vcertain neu and useful Im rovements in Detachable Counterbalanceeights .for Motor Crank- Shafts, of Which-the follovvingis a' speciiication. s, .p

My invention relates todetachable counterbalances for motor crankshafts', beingfan improvement on my pending application filed May12, 1919, Serial No.A 294,236, Y p

Thev object of my'present invention-is to facilitate the application of vthe counterbalances' to the arm of the crankshaft by doing away with the necessity of providing a groove inl each of thecounterbalances Which is adapted to receive the crankshaft arm.

A further object.isfto'reducerthe thick-i ness ofthe metal centrallyof eaohweight to reduce the centrifugal effect at that point upon the fastening bolts. u

further object isto change of section'that, occurs along the corner ofthe grooves kin myV previous invention, and which results inbreaking` of the castings at this change of section which is Where the greatest strain comes When clamping theiweights to. over-sized shaft-arms so large that they seat on the sides of the groove instead of the bottom-,producing a wedge .action that-is tremendouslygreater than any possible strainthat can comel on a properly fitted Weight.V v f A further and final object is 'to provide a construction for detachable counterbalances for motor lcrankshaftsvvhich Will permit of their being individually fitted quicklyl and easily to leach individual lcrankshaft so that the:counterbalances mayv be made to fit the smallest sizey of shafts and yet be l perfectlyfitted to the overquickly and sized shafts. y. Y y l e 4 Figure l is `a view' offtvvo parts side by side of a counterbalance vie-Wed from the side that clamps against. thesh'aft arm.

Fig..2 is a section through the same along*l the length of the shaft arm. Y

Fig. 3 is -a section ofthe Weight Aat right angles to the length of the; shaft arm. i p y bis a lview similar .to Fig. 1, showing the relative opposite sides of said coun-f Y terbalance Weights. i

Fi rshows the two parts ofthe counterba ance facing each other as, they are liminate vthe sharp y p y K specifieation f Lettersratent. Patented Aug. 17, 1920. Aptucaxion mea september 24,1919, serial'No. 325,864.

When clamped` firmly together for shipment.` K V Y 'In manufacturing my former `counterbalance Weight `I have found that there is such a great variation in theforgedlporthere is no possibility of making any groove thatwill fit every shaft .of even one make' ofy motor Without special individual fitting.r

The result has been that I have had to make the'groove that fits overthe shaft arm Wide enoughto ,receive even the very largest size arm that can be-.met with in thel certain make of motorl crankshaft which a certain sizeof Weight 1s supposed to fit; otherwise .theaveights were apt to become broken in twovralong the lineV of Vthe corner,` ofthe grooves vvhen beingfclampedfto the arm of theV crankshaft, hence lthe groove became a very free fit for lthe. ordinary and underslzed arms.

.tions of the commercial crankshaft that Y The Weight as a Whole consists ofv tvvo. members hereinafter referred to as the bolt tween. lt will be seenthat-the bolt half l of the counterbalance.isprovided vWith, a blockS passed betWeenthe two bolt holes ses 9,-9so as to register against a facefof the) head offeachfclamping bolt/and prevent same fromturning. The holes 9,-9 area close fit for theclampin'g bolts. The nut halfv is provided'rivith holes lO-ll()` for the clamping bolts and Ithese holes areY rather Y free fit for the clamping bolts so that ingn- The innerside of `each Weight 3 from which project the lugs 6-6 and 7 7 is pro-,p vided With a depression Which .slopes both.

ways toward .the center at anangleto lit the double taper of the edges of, the crankthe Weights 4vmay place themselves properly 1 regardless `ofmisalinement in the proper position of the bolt holes. The outside face. `of each web. is countersunk andV is surroundedby ribs'll Whichacts to protect "the nuts and bolt heads, and strengthen the castshaft arm. At the center of this depression is a recess 12, which permits shifting ofthe weight along the shaft arm and Vwhich runs longitudinally "of the weband at rightv angles to the shaft arm and' includes the clamping boltholes 9 9 and 10-'10; thusv the depression which allows shifting the weight along the arm also decreases the thickness of thermetal which must bedrilled through in drilling the clamping bolt holes.

It will thus be seen thatthrough my new' construction' the time and expense of clean.

ing the corners of the lugs is saved as they are to belile fitted for each individual. crankshaft by the purchaser. l at vthe center of the counterbalance has been reduced so that with the same total weight of'met'al a greater balance and .flywheel effeet' may be obtained. The thickness of the metal to be drilled has been reduced to about 50%"VV of that required my former con-y struction. Furthermore, there is no sharp' hangs in section such as yexisted along the corner of thegroovc lin my former construction so that this weak spot in the casting has `been eliminated. No wedge effect is possiblev that will be great enough to break' the weight` as the worst carelessness in: fitting can only result in cracking off 'onelor moreV ofthe alinement lugs, and finally my new construction provides a counterbalance weight whichv will be closely fitted Ato all varieties of crankshaftsizes easily when they are installed and at the same time this' and an oblique center connecting the weighty ed ends,'the` inner faces of the .oblique centers .provided withV lugs between which theA obliquearms of the crankshaft are received. with the weighted Vends of each member dis-- osed on the opposite sides vof the arms,`

olts extending 'transversely of the` centers of the twomembers Vfor securing the coun'- terbalances to the arms of thecrank shaft.;

2, A crankshaft c'ounterbalancev including Y twomembers having weightedouter endsV and, anl 'oblique' center VVconnectingthe7 weighted ends,the inner. faces of the obliquecenters provided with lugs between which the" oblique arms ofthe crankshaft are received with` the weighted endsof `each .member vto disposed on the opposite sides of the arms, bolts extending transversely' of the centers of the two members for securing thecounterbalancesto the' arms of thel crankshaft and common means for preventing the bolts 3. crankshaft cou'nterbala-nce` including twomembersV having 'weighted outer ends' The weight I va web arranged in the/cavitiesfor -a-nd an oblique Vcenter connecting the weighted ends, the -inner faces of the oblique centers provided with lugs between which the obliquev armsof-the crankshaft are received with the weighted ends of each member Vdisposed on the opposite sidesY of the arms, bolts extending transversely of the centers of the twoniembers for securing the K- counterbalances to the arms of the crank-` shaft, cavities inone of the centers for re` ceiving the bolt heads and a web arranged in thecavitiesfor'preventing the bolts from turning. i

4. A vcrankshaft counterba'lance including two members having ,weighted outer ends and an obliquely disposed center.` connect-V ing the weighted ends, the4` inner Afaces ofthe oblique centers sloping inwardly and `recessed longitudinallythereof to' bridge the thickest portionfotthe crankshaft arm, and means extendingtransversely ofthe webs for securing 'the' counterbalance to the; crankshaft'arm.

Y 5. A. crankshaft co'unterbalance` including two members having weighted 'outerV endsV and an obliquely disposed center connecting the weighted ends, the inner faccsfof the oblique 'centers sloping Yj inwardly and re-l cessed longitudinally thereof to'V bridge the thickest portion ofthe V4crankshaft arm,'said sloping surfacesv providedl with` lugs 'on the outer edges thereof between which the' oblique armofY thel crankshaft is received with the weighted ends of` each member dis-Y posed onopposite sides ofth'earm and bolts extending transversely of the' centers of theV two members for securing the counterbal. ances thereon. l

recessed longitudinally thereof Ito bridge A the` thickest portion "of the said crankshaft arm, .said sloping` lsurfaces provided with lugs on' the outer edgestrthereof. between membertdisposed.y on' opposite, sides of the arm,- bolts extending"'transversely of vthe centers ofthe two members for securinglthe" counterbalances thereon, cavities inzone of'` the' centers for receiving the bolt heads and l l a prevent-A infr the bolts'from turning; 'i y Acrankeshaft counterbalancefcompiis ing two opposed weight'sfor applicationto haft, means lfoi` clamping said members toigeth'er against the `edges Vof said crank-shaft,

nd alinement lugsarranged-on 'the inner aces `of said weights, between `whichtfhe rms are received.` 1 f' 8. A 'crank-shaft icounterbalance compriswhich the oblique arm.' of 'the crankshaftfis received with' the weighted endrof eachl the oppositeedges ofthearm ofthe `cran'kof `joined opposed Weights for application Y to the opposite edges of the arm of a crankshaft7 means extending transversely of thev crankshaft for clamping said two members together against the edges of said crankshaft, and means projecting from the inner faces of the Weights between Which the arm of the crank-shaft is vreceived and a1ined.

9. 'A crank-shaft counterbalance comprising two opposed weights Jfor application yto the opposite edges of the arm 0I' the crank-v shaft, means for Clamping said members t0- gether against the edges of said oiankshaft, and means projecting from the inner faces of the Weights. between which the arm vof the crank-shaft is received and alined.

In testimony whereof I affix my signature.

ROLLAND S. TROTT. 

